One of the basic properties of a soft drink is its acidity. With
the exception of soda water, soft drinks are acidified by the
addition of fruit juice or by the inclusion of an acid.
Acids are used in soft drinks to fulfil two main functions:
1. To inhibit the growth of micro-organisms such as yeasts,
moulds and bacteria.
2. To improve the taste profile of a drink by balancing the
A number of acids can be used in soft drinks including tartaric
and lactic acids. However, the three most commonly used acids are
citric, malic and phosphoric. Citric acid (E330) is found in citrus
fruits, blackcurrants, strawberries and raspberries. Malic acid
(E296) is found in apples, cherries, plums and peaches. Phosphoric acid is a strong mineral acid used in
cola drinks to provide their characteristic taste.
The amount of acid used in soft drinks depends on the individual
product recipe and the type of acid used; the stronger the acid the
less is required to make the final drink. For example very little
phosphoric acid needs to be added to a cola drink as it is a very
Acidic soft drinks and dental health
Many food and drink products such as fruit, sauces, pickle and
wine contain acid, whether natural or added, in the same way that
soft drinks do. However an acid can only have an influence on
enamel erosion for as long as that acid is in contact with the
enamel surface of teeth.
Soft drinks normally have little contact with teeth when
compared to other foods. Studies on dental erosion have shown it to
be dependent on several different factors. This means that
susceptibility in individuals varies according to behaviour,
lifestyle, diet and oral hygiene practice. (See Health and Wellbeing).